The present invention relates to seals for operable location between confronting surfaces, and more particularly, to a seal for use in cooperation with low tolerance components with a relatively high engagement force, wherein the clearance between the components is relatively small. The present invention may be particularly configured for applications in automotive vehicles.
Seals are employed in numerous applications to reduce or inhibit the migration of environmental elements as well as noise across an interface. Seals must accommodate a variety of factors such as intended operating environment parameters, performance specifications and the tolerances of the relevant components and the resulting clearances to be sealed.
Traditional car door seals have been required to accommodate relatively large manufacturing tolerances as much as 12 mm or more. To address these relatively large tolerances, prior designs have employed a two component seal, wherein a first component of the seal is constructed to engage a portion of either the body or the door. A remaining portion of the seal provides a scaling interface and includes a generally hollow, bulbous or highly compressible portion sized to accommodate the clearance between the components as well as tolerances in the bulb.
Typically, a vehicle component such as a door would be manufactured with a nominal 12 mm gap, wherein an acceptable gap can be as large as 17 mm. Thus, as seal designs have developed, they have been required to accommodate the relatively large clearances or gaps between the confronting surfaces to be sealed.
However, developments in automotive design and manufacture are leading to reduced clearances. In addition, the tolerances in confronting surfaces are decreasing. Therefore, existing seals and seal constructions are incompatible with low tolerance and/or low clearance confronting surfaces that may become available in the automotive industry. Thus, a need exists for a seal design and construction that can accommodate confronting surfaces having a clearance of approximately 6 mm or less. The need also exists for a seal that can be operably located and retained in a low clearance environment.
Manufacturing techniques and materials developments have advanced so that traditional clearances of approximately 12 mm or more may no longer be accepted in the industry. Manufacturing ranges may provide a resulting clearance between the confronting surfaces that may be about 6 mm or less. However, the resulting clearance between the confronting surfaces must still be sealed. It is believed that Current seal designs cannot be operably located in the low clearance installations.
Anticipated low tolerance, high production volume installations include vehicle components such as doors, hoods, frames and panels that may be formed by molding. Alternatively, extruding or stamping can be used to form these components. As the confronting surfaces will have greatly reduced tolerances, the resulting clearances in the assembled components are often substantially reduced. Further, these components are often movable between a first open position and a second closed or adjacent position, wherein the components in the closed position are located within restricted clearances. These restricted clearances are likely to be on the order of approximately 6 mm or less.
The present invention provides a seal for confronting, low tolerance components cooperatively employed to form low clearances. The present seal is employed with components having relatively small manufacturing tolerances, such as those manufactured by molding or stamping. An example of such low tolerance manufactured components are those formed of molded materials such as polycarbonate or other high strength plastic materials. Typical molded components include doors and frames for vehicles such as automobiles, buses, trucks, vans and SUVs.
The present invention provides for a sealed interface between the movable components forming confronting surfaces in a vehicle, wherein the dimension of the clearance or interface to be sealed is on the order of 6 mm or less. The present seal includes a dense cellular structure, a foamed in place urethane, an EPDM, a TPE or a urethane, a high density EPDM or resilient layer which is bonded or connected to the relevant portion of the confronting surface such as a door and/or a frame. The particular polycarbonate or the density of the EPDM is selected in part based upon the intended operating parameters of the seal.
It is contemplated manufacture of the seal may be accomplished by bonding the seal to the confronting surface, such as a door and/or the frame at the time of manufacture in the molding, stamping or extruding process that forms the door and/or frame. Alternatively, the seal may be laminated to the door or the frame to form a chemical bond therebetween. In alternative constructions, retention of the seal relative to the confronting surfaces can be accomplished through combined mechanical and chemical bonds as well as mechanical bonds such as pins.